Alisal Reservoir water level — California

California · USGS · reading Aug 31, 2026, 12:15 AM (UTC-07:00) Provisional

Alisal Reservoir in California was last measured at 598.47 ft (datum NGVD29), as of Aug 31, 2026, 12:15 AM (UTC-07:00) (USGS Water Services). Over its recent trend window the level has been falling (−0.6 ft). This reading is provisional and subject to revision.

Current reading Alisal Reservoir · California
Pool elevation
598.47 ft

Datum NGVD29 · provisional, subject to revision. (Why datum matters →)

% of conservation pool full
Not reported
Storage
2,242 acre-ft
Recent trend
↓Falling

−0.6 ft over the trend window

Recent trend

Readings this station published between Jun 2, 2026 and Aug 31, 2026 — a 89-day window — downsampled for display.

599.9ft598.5ftJun 2 – Aug 31

Data: USGS Water Services (waterservices.usgs.gov) and USACE CWMS Data (cwms-data.usace.army.mil), retrieved 2026-08-31. Both public domain (a work of the U.S. Government, 17 U.S.C. §105).

Not for navigation or safety decisions (why →)

Source: USGS site 11128300, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00). Official page for this lake →

About this gauge's record

This site's drainage basin covers approximately 8 sq mi of contributing watershed.

The dam behind Alisal Reservoir

Alisal Reservoir is held back by Alisal Creek , an earthfill embankment, holding the pool back by sheer mass and an impervious core rather than by the strength of concrete , standing 93 ft high and running 1,100 ft along its crest , built across Alisal Creek in Santa Barbara County , near Alisal Ranch . It was completed in 1971 , and is owned by The Alisal Ranch (a private owner) .

Its recorded primary purpose is water supply — delivering water to its customers comes first, so drawdown here follows demand as much as it follows rainfall . It also serves water supply;irrigation;recreation.

NID classes it high hazard potential. That describes what a failure would cost downstream — loss of life would be expected — and says nothing about how likely a failure is, or what condition the dam is in. Its most recent condition assessment was satisfactory — no deficiencies recognised for expected loading. That assessment is dated 09/01/2017.

At its normal pool the reservoir covers about 97 acres. NID records a maximum storage of 2,342 acre-ft. It is regulated by DWR, Division of Safety of Dams.

Dam facts: National Inventory of Dams record CA00731 , filed by California — U.S. Army Corps of Engineers, public domain. Water levels above come from USGS Water Services and are a separate source. (How this dam was matched to this gauge →)

How Alisal Reservoir compares nearby

All 6 nearby lakes with a current trend are also falling, suggesting a regional pattern rather than an operation specific to this dam.

Nearby lakes

The six nearest published lakes by centroid distance (great-circle) — cross-state neighbors included.

Lakes nearest to Alisal Reservoir, with current level and distance.
Lake State Level Distance
Santa Ynez River CA 1,383.05 ft 41 km
Lake Piru CA 1,048.53 ft 127 km
Nacimiento Reservoir CA 750.91 ft 151 km
San Antonio Reservoir CA 741.12 ft 155 km
Isabella Dam CA 2,561.14 ft 194 km
Success Lake CA 606.13 ft 201 km

Frequently asked questions

What is the current water level of Alisal Reservoir?
As of Aug 31, 2026, 12:15 AM (UTC-07:00), the pool elevation was 598.47 ft (datum NGVD29), provisional and subject to revision. See the trend chart above for the recent direction.
Is Alisal Reservoir full right now?
Its managing agency does not publish a %-of-conservation-pool-full figure for this lake, so we show the bare level rather than estimate one.
Where does this data come from?
From USGS site 11128300, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00).

More in California

See every lake tracked in California, or read the methodology behind these figures.